1
|
Zhou J, Wang W, Liu D, Xu S, Wang X, Zhang X, Wang X, Li Y, Sheng L, Wang X, Xu B. Discovery of 2-Ethoxy-5-isobutyramido- N-1-substituted Benzamide Derivatives as Selective Kv2.1 Inhibitors with In Vivo Neuroprotective Effects. J Med Chem 2024; 67:213-233. [PMID: 38150670 DOI: 10.1021/acs.jmedchem.3c01245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Kv2.1 is involved in regulating neuronal excitability and neuronal cell apoptosis, and inhibiting Kv2.1 is a potential strategy to prevent cell death and achieve neuroprotection in ischemic stroke. In this work, a series of novel benzamide derivatives were designed and synthesized as Kv2.1 inhibitors, and extensive structure-activity relationships led to highly potent and selective Kv2.1 inhibitors having IC50 values of 10-8 M. Among them, compound 80 (IC50 = 0.07 μM, selectivity >130 fold over other K+, Na+, and Ca2+ ion channels) was able to decrease the apoptosis of HEK293/Kv2.1 cells induced by H2O2. Furthermore, its anti-ischemic efficacy was demonstrated as it markedly reduced the infarct volume in MCAO rat model. Additionally, compound 80 possessed appropriate plasma PK parameters. It could serve as a probe to investigate Kv2.1 pathological functions and deserved to be further explored.
Collapse
Affiliation(s)
- Jie Zhou
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Weiping Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Dong Liu
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shaofeng Xu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xue Wang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xinyuan Zhang
- Information Center, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xiaoyu Wang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yan Li
- Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Li Sheng
- Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xiaoliang Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Bailing Xu
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| |
Collapse
|
2
|
Guo R, Guo G, Wang A, Xu G, Lai R, Jin H. Spider-Venom Peptides: Structure, Bioactivity, Strategy, and Research Applications. Molecules 2023; 29:35. [PMID: 38202621 PMCID: PMC10779620 DOI: 10.3390/molecules29010035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/30/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024] Open
Abstract
Spiders (Araneae), having thrived for over 300 million years, exhibit remarkable diversity, with 47,000 described species and an estimated 150,000 species in existence. Evolving with intricate venom, spiders are nature's skilled predators. While only a small fraction of spiders pose a threat to humans, their venoms contain complex compounds, holding promise as drug leads. Spider venoms primarily serve to immobilize prey, achieved through neurotoxins targeting ion channels. Peptides constitute a major part of these venoms, displaying diverse pharmacological activities, and making them appealing for drug development. Moreover, spider-venom peptides have emerged as valuable tools for exploring human disease mechanisms. This review focuses on the roles of spider-venom peptides in spider survival strategies and their dual significance as pharmaceutical research tools. By integrating recent discoveries, it provides a comprehensive overview of these peptides, their targets, bioactivities, and their relevance in spider survival and medical research.
Collapse
Affiliation(s)
- Ruiyin Guo
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; (R.G.)
| | - Gang Guo
- The Third Affiliated Hospital of Kunming Medical University (Yunnan Cancer Hospital), Kunming 650118, China;
| | - Aili Wang
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; (R.G.)
| | - Gaochi Xu
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; (R.G.)
| | - Ren Lai
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; (R.G.)
- Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming-Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, China
| | - Hui Jin
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; (R.G.)
| |
Collapse
|
3
|
Matsumura K, Yokogawa M, Osawa M. Peptide Toxins Targeting KV Channels. Handb Exp Pharmacol 2021; 267:481-505. [PMID: 34117930 DOI: 10.1007/164_2021_500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A number of peptide toxins isolated from animals target potassium ion (K+) channels. Many of them are particularly known to inhibit voltage-gated K+ (KV) channels and are mainly classified into pore-blocking toxins or gating-modifier toxins. Pore-blocking toxins directly bind to the ion permeation pores of KV channels, thereby physically occluding them. In contrast, gating-modifier toxins bind to the voltage-sensor domains of KV channels, modulating their voltage-dependent conformational changes. These peptide toxins are useful molecular tools in revealing the structure-function relationship of KV channels and have potential for novel treatments for diseases related to KV channels. This review focuses on the inhibition mechanism of pore-blocking and gating-modifier toxins that target KV channels.
Collapse
Affiliation(s)
- Kazuki Matsumura
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Mariko Yokogawa
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan.
| |
Collapse
|
4
|
McArthur JR, Munasinghe NR, Finol-Urdaneta RK, Adams DJ, Christie MJ. Spider Venom Peptide Pn3a Inhibition of Primary Afferent High Voltage-Activated Calcium Channels. Front Pharmacol 2021; 11:633679. [PMID: 33584315 PMCID: PMC7875911 DOI: 10.3389/fphar.2020.633679] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 12/30/2020] [Indexed: 11/19/2022] Open
Abstract
Despite potently inhibiting the nociceptive voltage-gated sodium (Nav) channel, Nav1.7, µ-theraphotoxin Pn3a is antinociceptive only upon co-administration with sub-therapeutic opioid agonists, or by itself at doses >3,000-fold greater than its Nav1.7 IC50 by a yet undefined mechanism. Nav channels are structurally related to voltage-gated calcium (Cav) channels, Cav1 and Cav2. These channels mediate the high voltage-activated (HVA) calcium currents (ICa) that orchestrate synaptic transmission in nociceptive dorsal root ganglion (DRG) neurons and are fine-tuned by opioid receptor (OR) activity. Using whole-cell patch clamp recording, we found that Pn3a (10 µM) inhibits ∼55% of rat DRG neuron HVA-ICa and 60–80% of Cav1.2, Cav1.3, Cav2.1, and Cav2.2 mediated currents in HEK293 cells, with no inhibition of Cav2.3. As a major DRG ICa component, Cav2.2 inhibition by Pn3a (IC50 = 3.71 ± 0.21 µM) arises from an 18 mV hyperpolarizing shift in the voltage dependence of inactivation. We observed that co-application of Pn3a and µ-OR agonist DAMGO results in enhanced HVA-ICa inhibition in DRG neurons whereas co-application of Pn3a with the OR antagonist naloxone does not, underscoring HVA channels as shared targets of Pn3a and opioids. We provide evidence that Pn3a inhibits native and recombinant HVA Cavs at previously reportedly antinociceptive concentrations in animal pain models. We show additive modulation of DRG HVA-ICa by sequential application of low Pn3a doses and sub-therapeutic opioids ligands. We propose Pn3a's antinociceptive effects result, at least in part, from direct inhibition of HVA-ICa at high Pn3a doses, or through additive inhibition by low Pn3a and mild OR activation.
Collapse
Affiliation(s)
- Jeffrey R McArthur
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Nehan R Munasinghe
- Discipline of Pharmacology, University of Sydney, Sydney, NSW, Australia
| | - Rocio K Finol-Urdaneta
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia.,Electrophysiology Facility for Cell Phenotyping and Drug Discovery, IHMRI, Wollongong, NSW, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | | |
Collapse
|
5
|
Wang Y, Luo Z, Lei S, Li S, Li X, Yuan C. Effects and mechanism of gating modifier spider toxins on the hERG channel. Toxicon 2020; 189:56-64. [PMID: 33212100 DOI: 10.1016/j.toxicon.2020.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/11/2020] [Accepted: 11/15/2020] [Indexed: 10/23/2022]
Abstract
Jingzhaotoxin-I, -III, -IV, -XIII, and -35 (JZTX-I, -III, -IV, -XIII, and -35), gating modifier toxins isolated from the venom of the Chinese tarantula Chilobrachys Jingzhao, were reported to act on cardiac sodium channels and Kv channels. JZTX-I and JZTX-XIII inhibited the hERG channel with the IC50 value of 626.9 nM and 612.6 nM, respectively. JZTX-III, -IV, and -35 share high sequence similarity with JZTX-I and JZTX-XIII, but they showed much lower affinity on the hERG channel compared with JZTX-I and JZTX-XIII. The inhibitory potency of the above five toxins on the hERG channel was not in accordance with their affinity on the Nav1.5 and Kv2.1 channels, indicating that the bioactive surfaces of the five toxins interacting with hERG, Nav1.5 and Kv2.1 are at least in part different. Structure-function analysis of the gating modifier toxins suggested that the functional bioactive surface binding to the hERG channel consists of a conserved hydrophobic patch, surrounding acidic residues (Glu10 in JZTX-XIII, Glu11 in JZTX-I), and basic residues which may be different from residues binding to the Kv2.1 channel.
Collapse
Affiliation(s)
- Yingyi Wang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Zhengyi Luo
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Sheng Lei
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Shuji Li
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Xiaowen Li
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Chunhua Yuan
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| |
Collapse
|
6
|
Zhang Y, Luo J, He J, Rong M, Zeng X. JZTX-V Targets the Voltage Sensor in Kv4.2 to Inhibit I to Potassium Channels in Cardiomyocytes. Front Pharmacol 2019; 10:357. [PMID: 31040778 PMCID: PMC6476928 DOI: 10.3389/fphar.2019.00357] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 03/21/2019] [Indexed: 12/16/2022] Open
Abstract
Kv4 potassium channels are responsible for transient outward K+ currents in the cardiac action potential (AP). Previous experiments by our group demonstrated that Jingzhaotoxin-V (JZTX-V) selectively inhibits A-type potassium channels. However, the specific effects of JZTX-V on the transient outward (Ito) current of cardiomyocytes and underlying mechanism of action remain unclear. In the current study, 100 nM JZTX-V effectively inhibited the Ito current and extended the action potential duration (APD) of neonatal rat ventricular myocytes (NRVM). We further analyzed the effects of JZTX-V on Kv4.2, a cloned channel believed to underlie the Ito current in rat cardiomyocytes. JZTX-V inhibited the Kv4.2 current with a half-maximal inhibitory concentration (IC50) of 13 ± 1.7 nM. To establish the molecular mechanism underlying the inhibitory action of JZTX-V on Kv4.2, we performed alanine scanning mutagenesis of Kv4.2 and JZTX-V and assessed the effects of the mutations on binding activities of the proteins. Interestingly, the Kv4.2 mutations V285A, F289A, and V290A reduced the affinity for JZTX-V while I275A and L277A increased the affinity for JZTX-V. Moreover, mutation of positively charged residues (R20 and K22) of JZTX-V and the hydrophobic patch (formed by W5, M6, and W7) led to a significant reduction in toxin sensitivity, indicating that the hydrophobic patch and electrostatic interactions played key roles in the binding of JZTX-V with Kv4.2. Data from our study have shed light on the specific roles and molecular mechanisms of JZTX-V in the regulation of Ito potassium channels and supported its utility as a potential novel antiarrhythmic drug.
Collapse
Affiliation(s)
- Yiya Zhang
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Central South University, Changsha, China.,The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Ji Luo
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Juan He
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Mingqiang Rong
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiongzhi Zeng
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| |
Collapse
|
7
|
Cardoso FC, Lewis RJ. Structure-Function and Therapeutic Potential of Spider Venom-Derived Cysteine Knot Peptides Targeting Sodium Channels. Front Pharmacol 2019; 10:366. [PMID: 31031623 PMCID: PMC6470632 DOI: 10.3389/fphar.2019.00366] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 03/25/2019] [Indexed: 12/11/2022] Open
Abstract
Spider venom-derived cysteine knot peptides are a mega-diverse class of molecules that exhibit unique pharmacological properties to modulate key membrane protein targets. Voltage-gated sodium channels (NaV) are often targeted by these peptides to allosterically promote opening or closing of the channel by binding to structural domains outside the channel pore. These effects can result in modified pain responses, muscle paralysis, cardiac arrest, priapism, and numbness. Although such effects are often deleterious, subtype selective spider venom peptides are showing potential to treat a range of neurological disorders, including chronic pain and epilepsy. This review examines the structure–activity relationships of cysteine knot peptides from spider venoms that modulate NaV and discusses their potential as leads to novel therapies for neurological disorders.
Collapse
Affiliation(s)
- Fernanda C Cardoso
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Richard J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| |
Collapse
|
8
|
Tilley DC, Angueyra JM, Eum KS, Kim H, Chao LH, Peng AW, Sack JT. The tarantula toxin GxTx detains K + channel gating charges in their resting conformation. J Gen Physiol 2018; 151:292-315. [PMID: 30397012 PMCID: PMC6400525 DOI: 10.1085/jgp.201812213] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/01/2018] [Indexed: 11/20/2022] Open
Abstract
Allosteric ligands modulate protein activity by altering the energy landscape of conformational space in ligand-protein complexes. Here we investigate how ligand binding to a K+ channel's voltage sensor allosterically modulates opening of its K+-conductive pore. The tarantula venom peptide guangxitoxin-1E (GxTx) binds to the voltage sensors of the rat voltage-gated K+ (Kv) channel Kv2.1 and acts as a partial inverse agonist. When bound to GxTx, Kv2.1 activates more slowly, deactivates more rapidly, and requires more positive voltage to reach the same K+-conductance as the unbound channel. Further, activation kinetics are more sigmoidal, indicating that multiple conformational changes coupled to opening are modulated. Single-channel current amplitudes reveal that each channel opens to full conductance when GxTx is bound. Inhibition of Kv2.1 channels by GxTx results from decreased open probability due to increased occurrence of long-lived closed states; the time constant of the final pore opening step itself is not impacted by GxTx. When intracellular potential is less than 0 mV, GxTx traps the gating charges on Kv2.1's voltage sensors in their most intracellular position. Gating charges translocate at positive voltages, however, indicating that GxTx stabilizes the most intracellular conformation of the voltage sensors (their resting conformation). Kinetic modeling suggests a modulatory mechanism: GxTx reduces the probability of voltage sensors activating, giving the pore opening step less frequent opportunities to occur. This mechanism results in K+-conductance activation kinetics that are voltage-dependent, even if pore opening (the rate-limiting step) has no inherent voltage dependence. We conclude that GxTx stabilizes voltage sensors in a resting conformation, and inhibits K+ currents by limiting opportunities for the channel pore to open, but has little, if any, direct effect on the microscopic kinetics of pore opening. The impact of GxTx on channel gating suggests that Kv2.1's pore opening step does not involve movement of its voltage sensors.
Collapse
Affiliation(s)
- Drew C Tilley
- Department of Physiology & Membrane Biology, University of California, Davis, Davis, CA
| | - Juan M Angueyra
- Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA
| | - Kenneth S Eum
- Department of Physiology & Membrane Biology, University of California, Davis, Davis, CA.,Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA
| | - Heesoo Kim
- Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA
| | - Luke H Chao
- Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA
| | - Anthony W Peng
- Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA
| | - Jon T Sack
- Department of Physiology & Membrane Biology, University of California, Davis, Davis, CA .,Neurobiology Course, Marine Biological Laboratory, Woods Hole, MA.,Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA
| |
Collapse
|
9
|
Moyer BD, Murray JK, Ligutti J, Andrews K, Favreau P, Jordan JB, Lee JH, Liu D, Long J, Sham K, Shi L, Stöcklin R, Wu B, Yin R, Yu V, Zou A, Biswas K, Miranda LP. Pharmacological characterization of potent and selective NaV1.7 inhibitors engineered from Chilobrachys jingzhao tarantula venom peptide JzTx-V. PLoS One 2018; 13:e0196791. [PMID: 29723257 PMCID: PMC5933747 DOI: 10.1371/journal.pone.0196791] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/19/2018] [Indexed: 11/18/2022] Open
Abstract
Identification of voltage-gated sodium channel NaV1.7 inhibitors for chronic pain therapeutic development is an area of vigorous pursuit. In an effort to identify more potent leads compared to our previously reported GpTx-1 peptide series, electrophysiology screening of fractionated tarantula venom discovered the NaV1.7 inhibitory peptide JzTx-V from the Chinese earth tiger tarantula Chilobrachys jingzhao. The parent peptide displayed nominal selectivity over the skeletal muscle NaV1.4 channel. Attribute-based positional scan analoging identified a key Ile28Glu mutation that improved NaV1.4 selectivity over 100-fold, and further optimization yielded the potent and selective peptide leads AM-8145 and AM-0422. NMR analyses revealed that the Ile28Glu substitution changed peptide conformation, pointing to a structural rationale for the selectivity gains. AM-8145 and AM-0422 as well as GpTx-1 and HwTx-IV competed for ProTx-II binding in HEK293 cells expressing human NaV1.7, suggesting that these NaV1.7 inhibitory peptides interact with a similar binding site. AM-8145 potently blocked native tetrodotoxin-sensitive (TTX-S) channels in mouse dorsal root ganglia (DRG) neurons, exhibited 30- to 120-fold selectivity over other human TTX-S channels and exhibited over 1,000-fold selectivity over other human tetrodotoxin-resistant (TTX-R) channels. Leveraging NaV1.7-NaV1.5 chimeras containing various voltage-sensor and pore regions, AM-8145 mapped to the second voltage-sensor domain of NaV1.7. AM-0422, but not the inactive peptide analog AM-8374, dose-dependently blocked capsaicin-induced DRG neuron action potential firing using a multi-electrode array readout and mechanically-induced C-fiber spiking in a saphenous skin-nerve preparation. Collectively, AM-8145 and AM-0422 represent potent, new engineered NaV1.7 inhibitory peptides derived from the JzTx-V scaffold with improved NaV selectivity and biological activity in blocking action potential firing in both DRG neurons and C-fibers.
Collapse
Affiliation(s)
- Bryan D. Moyer
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
- * E-mail:
| | - Justin K. Murray
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Joseph Ligutti
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Kristin Andrews
- Molecular Engineering, Amgen Discovery Research, Cambridge, Massachusetts, United States of America
| | | | - John B. Jordan
- Discovery Attribute Sciences, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Josie H. Lee
- Neuroscience, Amgen Discovery Research, Cambridge, Massachusetts, United States of America
| | - Dong Liu
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Jason Long
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Kelvin Sham
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Licheng Shi
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Reto Stöcklin
- Atheris Laboratories, CH Bernex, Geneva, Switzerland
| | - Bin Wu
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Ruoyuan Yin
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Violeta Yu
- Neuroscience, Amgen Discovery Research, Cambridge, Massachusetts, United States of America
| | - Anruo Zou
- Neuroscience, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Kaustav Biswas
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| | - Les P. Miranda
- Therapeutic Discovery, Amgen Discovery Research, Thousand Oaks, California, United States of America
| |
Collapse
|
10
|
Yao M, Wang J, Wu L, Min L, Li WY, Zhu LY, Meng E, Zhang DY. An efficient strategy for the expression of Jingzhaotoxin-III in Escherichia coli. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1304182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
|
11
|
Tao H, Chen X, Deng M, Xiao Y, Wu Y, Liu Z, Zhou S, He Y, Liang S. Interaction site for the inhibition of tarantula Jingzhaotoxin-XI on voltage-gated potassium channel Kv2.1. Toxicon 2016; 124:8-14. [PMID: 27810559 DOI: 10.1016/j.toxicon.2016.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 01/27/2023]
Abstract
Jingzhaotoxin-XI (JZTX-XI) is a 34-residue peptide from the Chinese tarantula Chilobrachys jingzhao venom that potently inhibits both voltage-gated sodium channel Nav1.5 and voltage-gated potassium channel Kv2.1. In the present study, we further showed that JZTX-XI blocked Kv2.1 currents with the IC50 value of 0.39 ± 0.06 μM. JZTX-XI significantly shifted the current-voltage (I-V) curves and normalized conductance-voltage (G-V) curves of Kv2.1 channel to more depolarized voltages. Ala-scanning mutagenesis analyses demonstrated that mutants I273A, F274A, and E277A reduced toxin binding affinity by 10-, 16-, and 18-fold, respectively, suggesting that three common residues (I273, F274, E277) in the Kv2.1 S3b segment contribute to the formation of JZTX-XI receptor site, and the acidic residue Glu at the position 277 in Kv2.1 is the most important residue for JZTX-XI sensitivity. A single replacement of E277 with Asp(D) increased toxin inhibitory activity. These results establish that JZTX-XI inhibits Kv2.1 activation by trapping the voltage sensor in the rested state through a similar mechanism to that of HaTx1, but these two toxins have small differences in the most crucial molecular determinant. Furthermore, the in-depth investigation of the subtle differences in molecular determinants may be useful for increasing our understanding of the molecular details regarding toxin-channel interactions.
Collapse
Affiliation(s)
- Huai Tao
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China; Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
| | - Xia Chen
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Meichun Deng
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan 410013, China
| | - Yucheng Xiao
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Yuanyuan Wu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Zhonghua Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Sainan Zhou
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Yingchun He
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China; Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Songping Liang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.
| |
Collapse
|
12
|
Abreu TF, Sumitomo BN, Nishiyama MY, Oliveira UC, Souza GHMF, Kitano ES, Zelanis A, Serrano SMT, Junqueira-de-Azevedo I, Silva PI, Tashima AK. Peptidomics of Acanthoscurria gomesiana spider venom reveals new toxins with potential antimicrobial activity. J Proteomics 2016; 151:232-242. [PMID: 27436114 DOI: 10.1016/j.jprot.2016.07.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 06/22/2016] [Accepted: 07/13/2016] [Indexed: 12/24/2022]
Abstract
Acanthoscurria gomesiana is a Brazilian spider from the Theraphosidae family inhabiting regions of Southeastern Brazil. Potent antimicrobial peptides as gomesin and acanthoscurrin have been discovered from the spider hemolymph in previous works. Spider venoms are also recognized as sources of biologically active peptides, however the venom peptidome of A. gomesiana remained unexplored to date. In this work, a MS-based workflow was applied to the investigation of the spider venom peptidome. Data-independent and data-dependent LC-MS/MS acquisitions of intact peptides and of peptides submitted to multiple enzyme digestions, followed by automated chromatographic alignment, de novo analysis, database and homology searches with manual validations showed that the venom is composed by <165 features, with masses ranging from 0.4-15.8kDa. From digestions, 135 peptides were identified from 17 proteins, including three new mature peptides: U1-TRTX-Agm1a, U1-TRTX-Agm2a and U1-TRTX-Agm3a, containing 3, 4 and 3 disulfide bonds, respectively. The toxins U1-TRTX-Agm1a differed by only one amino acid from U1-TRTX-Ap1a from A. paulensis and U1-TRTX-Agm2a was derived from the genicutoxin-D1 precursor from A. geniculata. These toxins have potential applications as antimicrobial agents, as the peptide fraction of A. gomesiana showed activity against Escherichia coli, Enterobacter cloacae and Candida albicans strains. MS data are available via ProteomeXchange Consortium with identifier PXD003884. BIOLOGICAL SIGNIFICANCE Biological fluids of the Acanthoscurria gomesiana spider are sources of active molecules, as is the case of antimicrobial peptides and acylpolyamines found in the hemolymphs. The venom is also a potential source of toxins with pharmacological and biotechnological applications. However, to our knowledge no A. gomesiana venom toxin structure has been determined to date. Using a combination of high resolution mass spectrometry, transcriptomics and bioinformatics, we employed a workflow to fully sequence, determine the number of disulfide bonds of mature peptides and we found new potential antimicrobial peptides. This workflow is suitable for complete peptide toxin sequencing when handling limited amount of venom samples and can accelerate the discovery of peptides with potential biotechnological applications.
Collapse
Affiliation(s)
- Thiago F Abreu
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Bianca N Sumitomo
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Milton Y Nishiyama
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - Ursula C Oliveira
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - Gustavo H M F Souza
- Mass Spectrometry Applications Research & Development Laboratory, Waters Corporation, Sāo Paulo, SP, Brazil
| | - Eduardo S Kitano
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - André Zelanis
- Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, ICT-UNIFESP, São José dos Campos, SP, Brazil
| | - Solange M T Serrano
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - Inácio Junqueira-de-Azevedo
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - Pedro I Silva
- Laboratório Especial de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo, SP, Brazil
| | - Alexandre K Tashima
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
| |
Collapse
|
13
|
Kuzmenkov AI, Grishin EV, Vassilevski AA. Diversity of Potassium Channel Ligands: Focus on Scorpion Toxins. BIOCHEMISTRY (MOSCOW) 2016; 80:1764-99. [DOI: 10.1134/s0006297915130118] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
14
|
Sesti F, Wu X, Liu S. Oxidation of KCNB1 K(+) channels in central nervous system and beyond. World J Biol Chem 2014; 5:85-92. [PMID: 24921000 PMCID: PMC4050120 DOI: 10.4331/wjbc.v5.i2.85] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/26/2014] [Accepted: 03/03/2014] [Indexed: 02/05/2023] Open
Abstract
KCNB1, a voltage-gated potassium (K(+)) channel that conducts a major delayed rectifier current in the brain, pancreas and cardiovascular system is a key player in apoptotic programs associated with oxidative stress. As a result, this protein represents a bona fide drug target for limiting the toxic effects of oxygen radicals. Until recently the consensus view was that reactive oxygen species trigger a pro-apoptotic surge in KCNB1 current via phosphorylation and SNARE-dependent incorporation of KCNB1 channels into the plasma membrane. However, new evidence shows that KCNB1 can be modified by oxidants and that oxidized KCNB1 channels can directly activate pro-apoptotic signaling pathways. Hence, a more articulated picture of the pro-apoptotic role of KCNB1 is emerging in which the protein induces cell's death through distinct molecular mechanisms and activation of multiple pathways. In this review article we discuss the diverse functional, toxic and protective roles that KCNB1 channels play in the major organs where they are expressed.
Collapse
|
15
|
The venom gland transcriptome of Latrodectus tredecimguttatus revealed by deep sequencing and cDNA library analysis. PLoS One 2013; 8:e81357. [PMID: 24312294 PMCID: PMC3842942 DOI: 10.1371/journal.pone.0081357] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 10/10/2013] [Indexed: 01/01/2023] Open
Abstract
Latrodectus tredecimguttatus, commonly known as black widow spider, is well known for its dangerous bite. Although its venom has been characterized extensively, some fundamental questions about its molecular composition remain unanswered. The limited transcriptome and genome data available prevent further understanding of spider venom at the molecular level. In the present study, we combined next-generation sequencing and conventional DNA sequencing to construct a venom gland transcriptome of the spider L. tredecimguttatus, which resulted in the identification of 9,666 and 480 high-confidence proteins among 34,334 de novo sequences and 1,024 cDNA sequences, respectively, by assembly, translation, filtering, quantification and annotation. Extensive functional analyses of these proteins indicated that mRNAs involved in RNA transport and spliceosome, protein translation, processing and transport were highly enriched in the venom gland, which is consistent with the specific function of venom glands, namely the production of toxins. Furthermore, we identified 146 toxin-like proteins forming 12 families, including 6 new families in this spider in which α-LTX-Lt1a family2 is firstly identified as a subfamily of α-LTX-Lt1a family. The toxins were classified according to their bioactivities into five categories that functioned in a coordinate way. Few ion channels were expressed in venom gland cells, suggesting a possible mechanism of protection from the attack of their own toxins. The present study provides a gland transcriptome profile and extends our understanding of the toxinome of spiders and coordination mechanism for toxin production in protein expression quantity.
Collapse
|
16
|
Tao H, Chen JJ, Xiao YC, Wu YY, Su HB, Li D, Wang HY, Deng MC, Wang MC, Liu ZH, Liang SP. Analysis of the Interaction of Tarantula Toxin Jingzhaotoxin-III (β-TRTX-Cj1α) with the Voltage Sensor of Kv2.1 Uncovers the Molecular Basis for Cross-Activities on Kv2.1 and Nav1.5 Channels. Biochemistry 2013; 52:7439-48. [DOI: 10.1021/bi4006418] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Huai Tao
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
- Department
of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Jin J. Chen
- College
of Biology Science and Technology, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Yu C. Xiao
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Yuan Y. Wu
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Hai B Su
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Dan Li
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Heng Y. Wang
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Mei C. Deng
- Department
of Biochemistry, School of Biological Science and Technology, Central South University, Changsha, Hunan 410013, China
| | - Mei C. Wang
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Zhong H. Liu
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| | - Song P. Liang
- Key
Laboratory of Protein Chemistry and Developmental Biology of Ministry
of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China
| |
Collapse
|
17
|
Molecular determinants for the tarantula toxin jingzhaotoxin-I interacting with potassium channel Kv2.1. Toxicon 2012; 63:129-36. [PMID: 23246579 DOI: 10.1016/j.toxicon.2012.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 12/01/2012] [Accepted: 12/05/2012] [Indexed: 11/24/2022]
Abstract
With high binding affinity and distinct pharmacological functions, animal toxins are powerful ligands to investigate the structure-function relationships of voltage-gated ion channels. Jingzhaotoxin-I (JZTX-I) is an important neurotoxin from the tarantula Chilobrachys jingzhao venom that inhibits both sodium and potassium channels. In our previous work, JZTX-I, as a gating modifier, is able to inhibit activation of the potassium channel subtype Kv2.1. However, its binding site on Kv2.1 remains unknown. In this study, using Ala-scanning mutagenesis strategy, we demonstrated that four residues (I273, F274, E277, and K280) in S3b-S4 motif contributed to the formation of JZTX-I binding site. The mutations I273A, F274A, E277A, and K280A reduced toxin binding affinity by 6-, 10-, 8-, and 7-fold, respectively. Taken together with our previous data that JZTX-I accelerated channel deactivation, these results suggest that JZTX-I inhibits Kv2.1 activation by docking onto the voltage sensor paddle and trapping the voltage sensor in the closed state.
Collapse
|
18
|
Schwartz EF, Mourão CBF, Moreira KG, Camargos TS, Mortari MR. Arthropod venoms: A vast arsenal of insecticidal neuropeptides. Biopolymers 2012. [DOI: 10.1002/bip.22100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
19
|
Yuan C, Liu Z, Hu W, Gao T, Liang S. JZTX-XIII, a Kv channel gating modifier toxin from Chinese tarantula Chilobrachys jingzhao. Toxicon 2012; 59:265-71. [DOI: 10.1016/j.toxicon.2011.11.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 10/22/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
|
20
|
Toxins that Modulate Ionic Channels as Tools for Exploring Insulin Secretion. Cell Mol Neurobiol 2010; 30:1275-81. [DOI: 10.1007/s10571-010-9586-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 09/02/2010] [Indexed: 01/26/2023]
|
21
|
Lee S, Milescu M, Jung HH, Lee JY, Bae CH, Lee CW, Kim HH, Swartz KJ, Kim JI. Solution structure of GxTX-1E, a high-affinity tarantula toxin interacting with voltage sensors in Kv2.1 potassium channels . Biochemistry 2010; 49:5134-42. [PMID: 20509680 DOI: 10.1021/bi100246u] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
GxTX-1E is a neurotoxin recently isolated from Plesiophrictus guangxiensis venom that inhibits the Kv2.1 channel in pancreatic beta-cells. The sequence of the toxin is related to those of previously studied tarantula toxins that interact with the voltage sensors in Kv channels, and GxTX-1E interacts with the Kv2.1 channel with unusually high affinity, making it particularly useful for structural and mechanistic studies. Here we determined the three-dimensional solution structure of GxTX-1E using NMR spectroscopy and compared it to that of several related tarantula toxins. The molecular structure of GxTX-1E is similar to those of tarantula toxins that target voltage sensors in Kv channels in that it contains an ICK motif, composed of beta-strands, and contains a prominent cluster of solvent-exposed hydrophobic residues surrounded by polar residues. When compared with the structure of SGTx1, a toxin for which mutagenesis data are available, the residue compositions of the two toxins are distinct in regions that are critical for activity, suggesting that their modes of binding to voltage sensors may be different. Interestingly, the structural architecture of GxTX-1E is also similar to that of JZTX-III, a tarantula toxin that interacts with Kv2.1 with low affinity. The most striking structural differences between GxTX-1E and JZTX-III are found in the orientation between the first and second cysteine loops and the C-terminal region of the toxins, suggesting that these regions of GxTX-1E are responsible for its high affinity.
Collapse
Affiliation(s)
- Seungkyu Lee
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Deng M, Kuang F, Sun Z, Tao H, Cai T, Zhong L, Chen Z, Xiao Y, Liang S. Jingzhaotoxin-IX, a novel gating modifier of both sodium and potassium channels from Chinese tarantula Chilobrachys jingzhao. Neuropharmacology 2009; 57:77-87. [DOI: 10.1016/j.neuropharm.2009.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 04/19/2009] [Accepted: 04/20/2009] [Indexed: 12/19/2022]
|
23
|
Chen J, Zhao L, Jiang L, Meng E, Zhang Y, Xiong X, Liang S. Transcriptome analysis revealed novel possible venom components and cellular processes of the tarantula Chilobrachys jingzhao venom gland. Toxicon 2008; 52:794-806. [DOI: 10.1016/j.toxicon.2008.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/03/2008] [Accepted: 08/12/2008] [Indexed: 11/30/2022]
|
24
|
Structure, function, and modification of the voltage sensor in voltage-gated ion channels. Cell Biochem Biophys 2008; 52:149-74. [PMID: 18989792 DOI: 10.1007/s12013-008-9032-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2008] [Indexed: 01/12/2023]
Abstract
Voltage-gated ion channels are crucial for both neuronal and cardiac excitability. Decades of research have begun to unravel the intriguing machinery behind voltage sensitivity. Although the details regarding the arrangement and movement in the voltage-sensor domain are still debated, consensus is slowly emerging. There are three competing conceptual models: the helical-screw, the transporter, and the paddle model. In this review we explore the structure of the activated voltage-sensor domain based on the recent X-ray structure of a chimera between Kv1.2 and Kv2.1. We also present a model for the closed state. From this we conclude that upon depolarization the voltage sensor S4 moves approximately 13 A outwards and rotates approximately 180 degrees, thus consistent with the helical-screw model. S4 also moves relative to S3b which is not consistent with the paddle model. One interesting feature of the voltage sensor is that it partially faces the lipid bilayer and therefore can interact both with the membrane itself and with physiological and pharmacological molecules reaching the channel from the membrane. This type of channel modulation is discussed together with other mechanisms for how voltage-sensitivity is modified. Small effects on voltage-sensitivity can have profound effects on excitability. Therefore, medical drugs designed to alter the voltage dependence offer an interesting way to regulate excitability.
Collapse
|
25
|
Yuan C, Liao Z, Zeng X, Dai L, Kuang F, Liang S. Jingzhaotoxin-XII, a gating modifier specific for Kv4.1 channels. Toxicon 2007; 50:646-52. [PMID: 17631373 DOI: 10.1016/j.toxicon.2007.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 05/15/2007] [Accepted: 05/29/2007] [Indexed: 01/17/2023]
Abstract
Jingzhaotoxin-XII (JZTX-XII), a 29-residue polypeptide, was purified from the venom of the Chinese tarantula Chilobrachys jingzhao. Electrophysiological recordings carried out in Xenopus laevis oocytes showed that JZTX-XII is specific for Kv4.1 channels, with the IC50 value of 0.363 microM. It interacts with the channels by modifying the gating behavior. JZTX-XII shares 80% sequence identity with phrixotoxin1, a potent inhibitor for Kv4.2 and Kv4.3 channels. Structure analysis indicates that the difference of the charge distribution in the interactive surface perhaps influences the specific pharmacology of the toxins. JZTX-XII should be a valuable tool for the investigation of the Kv4.1 channels.
Collapse
Affiliation(s)
- Chunhua Yuan
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, Life Science College, Hunan Normal University, Changsha 410081, PR China
| | | | | | | | | | | |
Collapse
|
26
|
Xiao Y, Li J, Deng M, Dai C, Liang S. Characterization of the excitatory mechanism induced by Jingzhaotoxin-I inhibiting sodium channel inactivation. Toxicon 2007; 50:507-17. [PMID: 17618665 DOI: 10.1016/j.toxicon.2007.04.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2007] [Revised: 04/15/2007] [Accepted: 04/23/2007] [Indexed: 10/23/2022]
Abstract
We have recently isolated a peptide neurotoxin, Jingzhaotoxin-I (JZTX-I), from Chinese tarantula Chilobrachys jingzhao venom that preferentially inhibits cardiac sodium channel inactivation and may define a new subclass of spider sodium channel toxins. In this study, we found that in contrast to other spider sodium channel toxins acting presynaptically rather than postsynaptically, JZTX-I augmented frog end-plate potential amplitudes and caused an increase in both nerve mediated and unmediated muscle twitches. Although JZTX-I does not negatively shift sodium channel activation threshold, an evident increase in muscle fasciculation was detected. In adult rat dorsal root ganglion neurons JZTX-I (1 microM) induced a significant sustained tetrodotoxin-sensitive (TTX-S) current that did not decay completely during 500 ms and was inhibited by 0.1 microM TTX or depolarization due to voltage-dependent acceleration of toxin dissociation. Moreover, JZTX-I decreased closed-state inactivation and increased the rate of recovery of sodium channels, which led to an augmentation in TTX-S ramp currents and decreasing the amount of inactivation in a use-dependant manner. Together, these data suggest that JZTX-I acted both presynaptically and postsynaptically and facilitated the neurotransmitter release by biasing the activities of sodium channels towards open state. These actions are similar to those of scorpion alpha-toxin Lqh II.
Collapse
Affiliation(s)
- Yucheng Xiao
- Life Sciences College, Hunan Normal University, Changsha, Hunan 410081, PR China
| | | | | | | | | |
Collapse
|